The first rule changes stemming from Liberty's involvement in F1's technical working group are coming in 2019. A minimum driver + seat weight of 80kg and a change to the bargeboards and rear wing endplates for sponsor visibility.
https://www.motorsport.com/f1/news/fia- ... lo-997615/
https://www.motorsport.com/f1/news/team ... 19-997827/
The driver weight seems eminently sensible to me, and something I've personally wanted for many years. Even though the total car weight will increase at the same time, so the penalty for driver weight is ever reducing. Hopefully this will benefit the heavier drivers like Hulkenburg and Grosjean (maybe Eriksson), who despite being as fit and healthy as the rest are disadvantaged by nothing else but their genetics.
The second one I'm not sure has any significant benefit/detriment beyond sponsor exposure, but the barge boards will be lowered for better visibility of the cockpit sides, and the louvres will be removed from the rear wing endplates to achieve an unbroken surface.